Solve the system of equations by substitution. x +  y =  x + 7y = 8

Perform the required operations on the following functions given: f(x)= 3-x; g(x)= -2x find g[f(x)]

Solve with work adding cheese to a mcdonalds quarter pounder increases the fat content from 21g to 30g. what is the percent of change ?

A50% increase followed by 33 1/2% decrease